In regenerative medicine in which diseases are treated using the cells of a patient or the cells of a person other than the patient, cells extracted from a living body are often cultured to increase the number of cells, or tissue is grown in a certain form, and then used for transplantation treatment. Cells used for treatment have to be cultured in a clean room for cell culture, which is referred to as a cell processing center (CPC), in compliance with the good manufacturing practice (GMP). Problems here are in that cell culture is conducted by biologists and the preparation of cells for a patient takes a lot of effort, time, and costs, and in that risks of biological contamination arise by manual manipulation.
For the schemes of solving the problems, a system that automates cell culture processes in a closed system is developed. The automatic system includes a closed culture vessel that needs no manipulation of opening and closing the lid of the culture vessel, a liquid sending system, and an air supply system. In the entire automatic system, cells are cultured in the sealed state in which bacterial cells and viruses are prevented from entering. Thus, the cell culture processes are automated, and the risks of biological contamination are reduced.
On the other hand, in cells, some cell species need a growth factor produced from vegetative cells, which are feeder cells, in the process of growing cells, whereas some cell species need no growth factor. Cell species, such as embryonic stem (ES) cells and induced pluripotent stem (iPS) cells, on which attention is focused in regenerative medicine, skin epidermal cells, corneal epithelial cells, and oral epithelial cells, usually need feeder cells. In the case in which cultured cells are used for treatment, cells used for feeder cells and for treatment are desirably cultured as the cells are isolated from each other, and desirably cultured in a cell culture vessel having two culture layers. For schemes for solving this problem, a culture system described in Patent Literature 1 is proposed. In this system, a cell culture vessel having two culture layers is used and a flow channel that supplies or discharges cells or a culture medium is provided. Thus, cell species, such as ES cells, can be automatically cultured in a closed system. A culture system described in Patent Literature 2 is proposed as a system that implements automatic culture of cell species with no need of feeder cells in the process of growing cells. Patent Literature 2 discloses an automatic culture system that cultures cells, which are mainly stem cells, in a single culture layer.